1. Field of the Invention
This invention relates to bale-wrapping apparatus.
2. Description of the Prior Art
Bale-wrapping apparatus are generally known for wrapping cylindrical bales with protective wrapping materials, e.g., synthetic plastic sheet materials. The cylindrical bales may be formed from any suitable farm-produced substances which may have been prepared for feeding farm animals. One type of wrapping apparatus which has been described wraps an individual bale which is then discharged from the apparatus. Examples of this type of wrapping apparatus were described in various patents including U.S. Pat. Nos: 4,697,402; 5,020,299; 5,048,271; and 5,079,898; and Canadian Patent Numbers: 1,248,864; 1,271,405; and 1,318,235.
In another type of apparatus, the bales were disposed in sequence in a unitary protective covering. For instance, in U.S. Pat. No. 5,392,591, a netting machine was described which wraps a net around rectangular bales using longitudinally-extending netting material. In Canadian Patent Number 1,255,147, a wrapping method was described in which a prepared tube of weatherproof material was gathered and cylindrical bales were pushed end-to-end into the tube which was caused to extend from its gathered state.
U.S. Pat. No. 5,012,631 described a self-propelled apparatus having an engine-driven infeed conveyor synchronized in speed with an output conveyor. The cylindrical bales were passed through a hoop which carried sheet-wrapping material upon a spool, the sheet-wrapping material being wrapped around the cylindrical bales to provide the covering. A problem with apparatus of this type was that the bales may not contact each other end-to-end and loose packing may result with the wrapping material extending across gaps between the cylindrical bales.
Another U.S. Pat. No. 5,152,125 described a cylindrical bale-wrapping apparatus having a hoop carrying a wrapping spool and in which the cylindrical bales were fed through the hoop by a ram as wrapping proceeded.
Yet another bale-wrapping apparatus was described in U.S. Pat. No. 4,793,124. In this particular patent, two hoops were essential to the operation of the apparatus, the hoops being concentric, one within the other, with freely rotatable wheels held between the hoops to enable rotation of one hoop while the other one was held stationary.